Symptoms usually include a cough, fever, nasal congestion and shortness of breath. Infection may progress to bronchitis or pneumonia. Patients typically present with symptoms commonly seen in RSV infection but generally show less severe signs of respiratory distress. In most cases infection tends to be mild and self-limiting.

Infection occurs via contact with contaminated secretions and respiratory droplets. The incubation period of hMPV is 3-9 days and the median duration of illness can vary depending on severity of illness. The period of infectivity is typically 1-2 weeks in otherwise healthy patients, but may be prolonged in the face of immunodeficiency.